Yet Again, Science Says Teen Pot Smoking Does NOT Lower IQ — Even With Habitual Use

As much a political weapon as miracle treatment for myriad physical and mental ailments, cannabis has endured decades of embarrassingly inaccurate propaganda meant to instill an air of criminality and shame with its use — in particular, claims spewed by drug warrior politicians and the corporate press, that regular pot smokers are damaging their IQs.

Unsurprisingly — at least to the untold thousands of people benefiting medically, psychologically, and, yes, recreationally, as well as to the researchers of a voluminous, cumulative body of evidence proving cannabis’ sweeping potential — they were wrong.

Examining the relationship between IQ and cannabis use, researchers from the United States and United Kingdom “found that youth who used cannabis … had lower IQ at age 18, but there was little evidence that cannabis use was associated with IQ decline from age 12 to 18. Moreover, although cannabis use was associated with lower IQ and poorer executive functions at age 18, these associations were generally not apparent within pairs of twins from the same family, suggesting that family background factors explain why adolescents who use cannabis perform worse on IQ and executive function tests.”

And, in fact, “Short-term cannabis use in adolescence does not appear to cause IQ decline or impair executive functions, even when cannabis use reaches the level of dependence.”

“In the largest longitudinal examination of marijuana use and IQ change,” researchers from the University of California Los Angeles and the University of Minnesota concluded in a cognate 2016 study, “we find little evidence to suggest that adolescent marijuana use has a direct effect on intellectual decline. …[T]he lack of a dose–response relationship, and an absence of meaningful differences between discordant siblings lead us to conclude that the deficits observed in marijuana users are attributable to confounding factors that influence both substance initiation and IQ rather than a neurotoxic effect of marijuana.”

Another study published in the Journal of Psychopharmacology the same year mimicked those results, AlterNet notes. Assessing the intelligence quotient and academic fitness of 2,235 adolescent twins, investigators found — after accounting for external factors like tobacco and alcohol — teen cannabis enthusiasts “did not differ from never-users on either IQ or educational performance.”

Then, this month, conclusions by University of Florida researchers in still another study — a 14-year analysis of cannabis exposure and intelligence — affirmed results of the others. Writing in the journal Drug and Alcohol Dependence on August 1, investigators asserted, “our findings did not reveal a significant association between cumulative marijuana use and changes in intelligence scores.”

Much of the vocal anti-cannabis cadre cite impossibly flawed research from New Zealand, published in the Proceedings of the National Academy of Sciences in 2012, which found — thanks to their failure to account for extenuating factors such as the consumption of additional substances — a minimal reduction of six to eight points in IQ among those smoking cannabis beginning in early adolescence, and continuing through age 38.

Two subsequent related studies verily dispute the oft-cited lower-IQ analysis, contending the original authors’ skewed research too significantly — through the omission of both subject socioeconomic data and on individual use of tobacco and so on — to merit peer confirmation of the results.

It would be entirely possible, in other words, for the drop in IQ over the tested time period to have resulted from factors other than the cannabis studied — and that persistent adolescent consumption of the herb on academic performance should imperatively be considered “non-significant after controlling for persistent alcohol and tobacco use.”

Politicians, desperate to continue manning the helm as the titanic travesty known as the Drug War tanks ever quicker beneath the surface under the monumental burdens of overcriminalization, excessive-incarceration, and asinine propaganda so insulting to the public in an age where information sits split seconds away.

Thankfully, Americans have had enough of politicized, harmful laws, like cannabis prohibition, and — thanks in large part to disinfo-busting studies like those cited here — refuse to have their intelligence insulted by the stalest of all the mothball-laden anti-pot propaganda.